A lesson in history: Only two presidents have been impeached by the House and none have been convicted by the Senate, Nixon was threatened with impeachment but resigned in disgrace.
The worst scenario I can see for tRump is that he is utterly disgraced. Perhaps, given his egomania and threatened with indictments once he steps down, I suspect he would do all he can to stay in office until the ohso bitter end. I doubt the great man would step down unless Mueller and “the government” offered some sort of plea deal and even that would be impossible because he would still be subject to state charges and civil charges. So, we would have at least a year of a butter recluse in the White House while somebody else ran on the GOP ticket.
The GOP would then be in a pickle. Pence would be a terrible candidate. Even if not touched by Mueller, Pence’ ohso white, somber not gay persona would notsell well in 2020. They would need someone very clean and statesman like. ROMNEY.
To make this more palatble they might run Romney with Tim Scott or, if the lesson of Plain has not set in, perhpas Jody Ernst.
So you see better scenarios for Trump? With perhaps Pence being the only other alternative for the GOP as the man is sitting in the proverbial cat bird seat.